Question

Carbonate deposits from brine on ice cans can be controlled to a great extent by

A) adding sodium dichromate to the brine
B) increasing the pH to 8 for a period of time
C) adding calcium chloride to the brine solution
D) decreasing the pH to slightly under 7 for a period of time

Answer 1

To control carbonate deposits from brine, adjusting the pH to increase it to around 8 can be effective. This causes calcium ions to precipitate as insoluble carbonates, reducing the formation of scale.

Step-by-step explanation:

Controlling Carbonate Deposits from Brine

To control carbonate deposits from brine in ice cans, the concentration of anions in the solution can be influenced by adjusting the pH of the solution. This method allows for the selective precipitation of cations. By increasing pH through the addition of compounds like sodium carbonate, the carbonate anion is formed which can precipitate calcium carbonate, as calcium carbonate is significantly less soluble than calcium bicarbonate.

Based on the given choices, increasing the pH to 8 for a period of time is a viable option for controlling carbonate deposits from brine. This adjustment helps in the selective precipitation of cations, specifically calcium ions, as insoluble carbonates. If the pH is increased significantly, the formation of carbon dioxide and water can occur, which shifts the equilibrium and reduces the potential for carbonate deposition.